A new study says there’s a consensus forming on how to fix one of the most stubborn social problems: homelessness.

The study by Stephen Gaetz, director of the Canadian Homelessness Research Network, pulls together research from across Canada and the United States, which suggests it’s far cheaper to give a homeless person a place to live than to provide a patchwork of emergency services.

Mr. Gaetz says governments spend at least $4.5-billion a year dealing with homeless people, including the costs of emergency health care, mental-health services, law enforcement, shelters and food banks.